/**
  * unset connection
  *
  * unsets connection with seminar
  * @access public
  * @param string $seminar_id seminar-id
  * @return boolean successful
  */
 function unsetConnection($seminar_id)
 {
     global $connected_cms, $messages;
     $connected_cms[$this->cms_type]->soap_client->setCachingStatus(false);
     if ($this->getObjectId() != false) {
         $connected_cms[$this->cms_type]->soap_client->deleteObject($this->getId());
     }
     return parent::unsetConnection($seminar_id);
     $messages["error"] .= _("Die Zuordnung konnte nicht entfernt werden.");
     return false;
 }